2018-05-24T08:09:10ZSynthesis of Human Skin Pigmentation Disordershttps://diglib.eg.org:443/handle/10.1111/cgf12943
Synthesis of Human Skin Pigmentation Disorders
Barros, R. S.; Walter, M.
Chen, Min and Zhang, Hao (Richard)
Changes in the human pigmentary system can lead to imbalances in the distribution of melanin in the skin resulting in artefacts known as pigmented lesions. Our work takes as departing point biological data regarding human skin, the pigmentary system and the melanocytes life cycle and presents a reaction–diffusion model for the simulation of the shape features of human‐pigmented lesions. The simulation of such disorders has many applications in dermatology, for instance, to assist dermatologists in diagnosis and training related to pigmentation disorders. Our study focuses, however, on applications related to computer graphics. Thus, we also present a method to seamless blend the results of our simulation model in images of healthy human skin. In this context, our model contributes to the generation of more realistic skin textures and therefore more realistic human models. In order to assess the quality of our results, we measured and compared the characteristics of the shape of real and synthesized pigmented lesions. We show that synthesized and real lesions have no statistically significant differences in their shape features. Visually, our results also compare favourably with images of real lesions, being virtually indistinguishable from real images.Changes in the human pigmentary system can lead to imbalances in the distribution of melanin in the skin resulting in artefacts known as pigmented lesions. Our work takes as departing point biological data regarding human skin, the pigmentary system and the melanocytes life cycle and presents a reaction‐diffusion model for the simulation of the shape features of human‐pigmented lesions. The simulation of such disorders has many applications in dermatology, for instance, to assist dermatologists in diagnosis and training related to pigmentation disorders. Our study focuses, however, on applications related to computer graphics. Thus, we also present a method to seamless blend the results of our simulation model in images of healthy human skin.
2017-01-01T00:00:00ZConstrained Convex Space Partition for Ray Tracing in Architectural Environmentshttps://diglib.eg.org:443/handle/10.1111/cgf12801
Constrained Convex Space Partition for Ray Tracing in Architectural Environments
Maria, M.; Horna, S.; Aveneau, L.
Chen, Min and Zhang, Hao (Richard)
This paper explores constrained convex space partition (CCSP) as a new acceleration structure for ray tracing. A CCSP is a graph, representing a space partition made up of empty convex volumes. The scene geometry is located on the boundary of the convex volumes. Therefore, each empty volume is bounded with two kinds of faces: occlusive ones (belonging to the scene geometry), and non‐occlusive ones. Given a ray, ray casting is performed by traversing the CCSP one volume at a time, until it hits the scene geometry. In this paper, this idea is applied to architectural scenes. We show that CCSP allows to cast several hundreds of millions of rays per second, even if they are not spatially coherent. Experiments are performed for large furnished buildings made up of hundreds of millions of polygons and containing thousands of light sources.This paper explores constrained convex space partition (CCSP) as a new acceleration structure for ray tracing. A CCSP is a graph, representing a space partition made up of empty convex volumes. The scene geometry is located on the boundary of the convex volumes. Therefore, each empty volume is bounded with two kinds of faces: occlusive ones (belonging to the scene geometry), and non‐occlusive ones. Given a ray, ray casting is performed by traversing the CCSP one volume at a time, until it hits the scene geometry. In this paper, this idea is applied to architectural scenes.We show that CCSP allows to cast several hundreds of millions of rays per second, even if they are not spatially coherent. Experiments are performed for large furnished buildings made up of hundreds of millions of polygons and containing thousands of light
sources.
2017-01-01T00:00:00ZA Survey of Surface Reconstruction from Point Cloudshttps://diglib.eg.org:443/handle/10.1111/cgf12802
A Survey of Surface Reconstruction from Point Clouds
Berger, Matthew; Tagliasacchi, Andrea; Seversky, Lee M.; Alliez, Pierre; Guennebaud, Gaël; Levine, Joshua A.; Sharf, Andrei; Silva, Claudio T.
Chen, Min and Zhang, Hao (Richard)
The area of surface reconstruction has seen substantial progress in the past two decades. The traditional problem addressed by surface reconstruction is to recover the digital representation of a physical shape that has been scanned, where the scanned data contain a wide variety of defects. While much of the earlier work has been focused on reconstructing a piece‐wise smooth representation of the original shape, recent work has taken on more specialized priors to address significantly challenging data imperfections, where the reconstruction can take on different representations—not necessarily the explicit geometry. We survey the field of surface reconstruction, and provide a categorization with respect to priors, data imperfections and reconstruction output. By considering a holistic view of surface reconstruction, we show a detailed characterization of the field, highlight similarities between diverse reconstruction techniques and provide directions for future work in surface reconstruction.The area of surface reconstruction has seen substantial progress in the past two decades. The traditional problem addressed by surface reconstruction is to recover the digital representation of a physical shape that has been scanned, where the scanned data contain a wide variety of defects. While much of the earlier work has been focused on reconstructing a piece‐wise smooth representation of the original shape, recent work has taken on more specialized priors to address significantly challenging data imperfections, where the reconstruction can take on different representations—not necessarily the explicit geometry
2017-01-01T00:00:00ZGraphs in Scientific Visualization: A Surveyhttps://diglib.eg.org:443/handle/10.1111/cgf12800
Graphs in Scientific Visualization: A Survey
Wang, Chaoli; Tao, Jun
Chen, Min and Zhang, Hao (Richard)
Graphs represent general node‐link diagrams and have long been utilized in scientific visualization for data organization and management. However, using graphs as a visual representation and interface for navigating and exploring scientific data sets has a much shorter history, yet the amount of work along this direction is clearly on the rise in recent years. In this paper, we take a holistic perspective and survey graph‐based representations and techniques for scientific visualization. Specifically, we classify these representations and techniques into four categories, namely partition‐wise, relationship‐wise, structure‐wise and provenance‐wise. We survey related publications in each category, explaining the roles of graphs in related work and highlighting their similarities and differences. At the end, we reexamine these related publications following the graph‐based visualization pipeline. We also point out research trends and remaining challenges in graph‐based representations and techniques for scientific visualization.Graphs represent general node‐link diagrams and have long been utilized in scientific visualization for data organization and management. However, using graphs as a visual representation and interface for navigating and exploring scientific data sets has a much shorter history, yet the amount of work along this direction is clearly on the rise in recent years. In this paper, we take a holistic perspective and survey graph‐based representations and techniques for scientific visualization.
2017-01-01T00:00:00Z